This invention relates to a yarn traversing apparatus for obtaining a wound yarn package at a high speed winding with a good wound shape and without cob-webbing.
More specifically, the present invention relates to a yarn traversing apparatus, which comprises at least one pair of rotary blades which rotate in opposite directions and a mechanism for transferring the yarn between the blades.
Conventionally known yarn traversing apparatus of the above-described type are, for example, disclosed in Japanese Patent Publication No. Sho 53-22178, Japanese Patent Publication No. Sho 46-36258, and Japanese Patent Laid-open No. Sho 59-194977.
However, in these conventionally known apparatus, the yarn temporarily becomes free i.e., the yarn becomes in an unstable condition, when the yarn is transferred from one of the oppositely rotating yarn guides to the other yarn guide. Accordingly, there occurs a disadvantage that the obtained yarn quality is deteriorated because high shoulders are formed at ends of the package corresponding to traverse ends.
Further, there occurs another disadvantage, which is sometimes referred to as "cob-webbing" and wherein a yarn wound on the shoulders is slipped down from the shoulders.
In addition, in the conventionally known apparatus, since a so called "free length", i.e., a distance from the yarn guide to the contact roller, becomes long, there occurs the result that excessively high shoulders occur.
Besides, in the conventional apparatus, when a yarn is wound at a high speed higher than 5,000 m/min, the yarn is fluctuated due to the moment of inertia when the traverse motion is reversed, and the above-described disadvantages are even further pronounced.
Furthermore, in the conventional apparatus, since a common guide rail is disposed corresponding to rotary blades which are rotating in opposite directions and since the rotary blades rotating in opposite directions are arranged adjacent to each other, the traverse speed cannot be set freely. As a result, the following problems are inherent to the apparatus.
When the yarn is moved from the center of the traverse stroke toward the end of the traverse stroke, the yarn is moved behind the movement of the rotary blade by a distance equal to a distance from the position of the rotary blade to the point where the yarn reaches the contact roller multiplied by tan .theta., wherein .theta. is a winding angle. Further, when the traverse motion of the yarn is reversed at the end of the traverse stroke, the winding angle .theta. is also reversed, and the movement of the yarn in a traversing direction is temporarily stopped while the traverse motion is reversed. Thus, high shoulders are generated at the ends of the obtained package. Accordingly, the yarn quality may be deteriorated because of the high shoulders, and cob-webbing may occur due to loosening of the yarn.